• Severe sore throat
  • Large red tonsils covered with pus
  • Swollen lymph nodes in the neck, armpits and groin
  • Fever for 7 - 14 days
  • Enlarged spleen (in 50% of children)
  • Blood smear showing many atypical (unusual) lymphocytes
  • Positive blood test for mononucleosis
  • This diagnosis must be confirmed by a physician

Cause – Mononucleosis (mono) is caused by the Epstein-Barr virus. This virus is transmitted in infected saliva through coughing, sneezing and kissing. Although mononucleosis can occur at any age, it occurs more often in 15 to 25 year-olds, possibly because of more intimate contacts with others. Contrary to popular belief, mono is not very contagious. Household contacts of your child rarely come down with it.

Expected Course – Most children have only mild symptoms for about 1 week. Even those with severe symptoms usually feel completely well in 2 to 4 weeks. Complications are rare and require hospitalization when they occur. The most common complication is dehydration from not drinking enough fluids. Breathing may be obstructed by enlarged tonsils, adenoids, and other lymph tissue in the back of the throat. On rare occasions, the enlarged spleen will rupture if the abdomen is hit or strained. Because over 90% of youngsters with mononucleosis will develop a severe rash if they receive ampicillin or amoxicillin, these medications should be avoided in this condition. In general, mononucleosis is neither lingering nor progressive. All symptoms are gone by 4 weeks after they first appeared.

Home Treatment for Mononucleosis

Fever and Pain Medicines – No specific medicine will cure mononucleosis. However, symptoms can usually be reduced by medicines. The pain of swollen lymph nodes, sore throats, and fever over 102'F can usually be relieved by appropriate doses of acetaminophen or ibuprofen. (Do not give either of these medications if your child is under 2 months old. Do not give Ibuprofen if your child is under 6 months old.)

Sore Throat Treatment – Older children over age 6 can gargle with warm salt water (1/2 teaspoon of salt per glass). Sucking on hard candies for children over 4 also relieves symptoms (butterscotch seems to be a soothing flavor). Over age 1, children can sip warm chicken broth.

Provide a Soft Diet – Since swollen tonsils can make some foods hard to swallow, provide a soft diet as long as necessary. To prevent dehydration, be sure that your youngster drinks enough fluids. Milk shakes and cold drinks are especially good. Avoid citrus fruits. Give a daily multiple vitamin pill until the appetite returns to normal.

Activity – Your child does not need to stay in bed. Bed rest will not shorten the course of the illness or reduce symptoms. Your child can select how much rest he needs. Usually children voluntarily slow down until the fever has resolved. Children can return to school when the fever is gone and they can swallow normally. Most children will want to be back to full activity in 2 to 4 weeks.

Precautions for an Enlarged Spleen – A blow to the abdomen can cause rupture of an enlarged spleen and bleeding. This is a surgical emergency. Therefore all children with mononucleosis should avoid contact sports for at least 4 weeks. Athletes especially must restrict their activity until the spleen returns to normal size by physical exam. We will check your child weekly until the spleen size returns to normal. Constipation and heavy lifting should also be avoided because of the sudden pressures they can put on the spleen.

Contagiousness – Infectious mononucleosis is most contagious while your child has a fever. After the fever, is gone, the virus is still carried in the saliva for up to 6 months, but in small amounts. Overall, mononucleosis is only slightly contagious from contacts. Boyfriends, girlfriends, roommates and relatives rarely get it. (The incubation period is 4 to 7 weeks after contact.) The person with mononucleosis does not need to be isolated. However, he should definitely use separate glasses and utensils and avoid kissing until the fever has been gone for several days.

Call our office IMMEDIATELY if

  • Your child develops difficulty breathing.
  • Your child becomes dehydrated.
  • Abdominal pain occurs (especially high on the left side).
  • Left shoulder pain occurs.
  • Your child starts acting very sick.

Within 24 hours if

  • Your child develops noisy breathing.
  • Your child can't drink enough fluids.
  • Sinus or ear pain occurs.
  • The fever isn't gone within 10 days.
  • Your child isn't back to school in 2 weeks.
  • You have other questions or concerns.

Written by Barton D. Schmitt, MD, pediatrician and author of Your Child's Health, Bantam Books, a book for parents.